Fifty years ago, the EU cracked the secret of its current success

When six western European countries including France and West Germany created the European Economic Community (EEC) in 1958, their combined population accounted for a touch under 6% of the world’s then 3bn people. A lot has happened in the ensuing 65 years, from German reunification to an extra billion or so Indians and several rejiggings of the global order. One constant has remained: the club today known as the European Union represents a touch under 6% of the world’s now 8bn people.

This is not because of the French authorities’ repeatedly dashed hopes for a continuous baby boom. Rather, of the 447m people now living in the EU, half are from 21 countries that acceded as part of seven waves of new entrants. The start of 2023 marks the 50th anniversary of the first enlargement. This ought to be the cause of champagne-popping in Brussels, a town that rarely misses an opportunity to celebrate a past milestone; a bash was recently held to mark the 35th anniversary of Erasmus, a university-exchange programme. Instead, a muted mood prevails. That is in part because the biggest joiner of the 1973 intake, Britain, later became the only country to leave the club. (Ireland and Denmark remain.) Nor is everyone a fan of enlargement, which has made the EU bigger but also more unwieldy. The prospect of another ten or so entrants being let in—mostly smallish states in the Balkans but also Ukraine, a country of 44m people—is as terrifying to some existing members as it is exhilarating to others.